Urinary tract infection after Ivermectin (Heartgard) in dogs

The FDA has received 52 reports of urinary tract infection in dogs after Ivermectin. That is 0.4% of all reports for this medicine, compared with 0.5% across reports for all dog medicines.

52Reports

56%Marked serious

29%Recovered

12%Died or euthanised

22 daysTypical onset

How soon it started

Same day

3 11%

1–2 days

3 11%

3–7 days

3 11%

1–4 weeks

8 29%

Over a month

11 39%

How the animals did

Recovered

11 21%

Recovered with lasting effects

4 7.7%

Still unwell when reported

20 38%

Died

1 1.9%

Euthanised

5 9.6%

Not known

11 21%

Problems reported at the same time

19 37%

18 35%

18 35%

10 19%

9 17%

9 17%

9 17%

8 15%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Ivermectin prevents heartworm disease (monthly).

Products with this ingredient include Heartgard. The FDA hides brand names in its public data, so these reports cover every product with the same active ingredients.

Some herding breeds (for example Collies) carry the MDR1 gene variant and can be more sensitive to this drug class at high doses.

Questions owners ask

Can Ivermectin cause urinary tract infection in dogs?: 52 reports link the two, but a report alone does not prove the medicine was the cause: other illnesses, other medicines or coincidence can be involved. Your vet can judge it for your animal.
How soon after a dose was it reported?: In half of the reports with dates, it started within 22 days of the first dose.
What should I do?: Don't give another dose until you've spoken to your vet, and keep the packaging so you can tell them the product and dose. Your vet can also report it to the FDA (or you can, through the manufacturer or FDA form 1932a).

Urinary tract infection with similar medicines

Urinary tract infection after Ivermectin + Pyrantel (Heartgard Plus) 135 reports · 0.1% of its reports
Urinary tract infection after Milbemycin Oxime + Spinosad (Trifexis) 337 reports · 0.3% of its reports
Urinary tract infection after Moxidectin (ProHeart 6) 111 reports · 0.2% of its reports
Urinary tract infection after Milbemycin Oxime + Praziquantel (Interceptor Plus) 147 reports · 0.5% of its reports
Urinary tract infection after Milbemycin Oxime (Interceptor) 50 reports · 0.2% of its reports
Urinary tract infection after Selamectin (Revolution) 34 reports · 0.1% of its reports

All reported side effects of Ivermectin in dogs · Medicines most reported with urinary tract infection